Double-acting, two-cycle internal-combustion engine



APPLICATION FILED SEPT. 24, 1920.

Patented June 6, 1922.

2 SHEETS-SHEET I.

R m W W A TTOR/VEYS H. R. SETZ. DOUBLE-ACTING TWO-CYCLE INTERNAL COMBUSTION ENGINE.

APPLICATION FILED SEPT-24,1920.

Patented June 6, 1922.

2 SHEETS-SHEET 2.

INVENTOR f/fi/VS E. 65 T2.

ATTORNEYS I srArEs PATENT OFF-ICE.

HANS R. SE'IZ, OF MANITOWOG, WISCONSIN.

DOUBLE-ACTING, TWO-CYCLE INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented J une 6, 1922.

Application filed September 24, 1920; Serial No. 412,464.

R. SETZ, a citithe same.

' centered This invention relates to' double-acting, two-cycle internal combustion engines of the type wherein the scavenging ports and exhaust ports are cylinder midway piston.

In one kind of engine of the general type referred to heretofore devised the cylinder consists of a one-piece casting comprising an inner wall and an outer wall or water jacket rigidly tied together. culty of obtaining. sound castings, a cylinder' of the construction above referred to has the more serious drawback of uncertain the. end positions of the strains originating in the casting itself when coolingin the mold .and augmented by the restrained contractions and expansions due to the inevitable temperature diflerences when the engine is in operation, which temperature differences are very difficult to control. These difiiculties are only slightly reduced, if, as has been tried, the cylinder is subdivided into several horizontally-divided sections, each of which comprises an inner Wall and an outer wall integrally connected together. In another form of double-acting,

two-cycle engine the cylinders are built up in sections in such a manner that each cylinder proper consists virtually of two liners of one-half the rigidly held at or near its outer end and slidably near its innerend in one common center section of the cylinder. This arrangement permits of unrestrained expansion and contraction of the cylinder wall, but it imposes difficulties in manufac ture and operation due to the joint at the center of the cylinder, between the liners, over which the piston has to travel at very nearl its. maximum velocity. A greater drawback of such a construction, however, consists in the very obvious limitation to engines of the type wherein only the exhaust ports are l cated at the cent r of the cyllocated in the side wall ofthe Aside from the difii-- full length of the cylinder connected to said bed inder, the scavenging air being admitted at the opposite ends of the cylinder through valves located in the combustion zone of the cylinder. l

The mam object of my invention is to overcome the above mentioned objectionable features or characteristics of double-acting,

two-cycle internal combustion engines and also to slmplify the construction of such enines.

To this end I have devised a double-acting engine in which the cylinders are so mounted that the central or intermediate portion of the inner wall of each cylinder is rigidly connected to a stationary supportingstructure and the end portions'of the inner wall of the cylinder are free to expand and contract longitudinally. Preferably the mountings for the cylinders are so constructed that each cylinder can be adjusted laterally slightly with relation to the supporting structure that carries it during the operation of l1n1ng up the cylinder with its co-operating crank thus materially simplifying the machining operations.

Figure 1 of the drawings is avertical longitudinal sectionalview of a double-acting, two-cycle internal combustion engine trating a slight modification of my invention.

Figure 3 is a horizontal section through the center portion of the cylinder shown in- Fi ure 1.

igure 4 is a vertical longitudinal sectional view of a modified cylinder constricted in accordance with my invention; an Y t Figure 5'is a detail-sectional view, illustrating a slight change that can be made in the engine shown in Figure 4. In the p in Figure 1 of the drawin 2 designates the A-frames of the engine which are mounted on the bed plate (not shown) in the planes of the main shaft bearings and plate by bolts orother suitable fastening devices, 4 desi ates the cross heads which slide in vertical cross head guides 5 on the A-frames '2, and 6 designates a beam-like member extending longitudinally of the engine and resting form of my invention illustrated constructed in accordance with my invensingle ports whose greater than that of the exhaust ports 10, so

the latter together and forming a support for the cylinders of the engine. Each of the cylinders consists of a plain cylindrical member 7 of the full length of the cylinder provided with an integral belt portion 8 which is located approximately midway between the extreme ends of the cylinder. This belt portion 8 isutilized to rigidly connect the central or intermediate portion of the cylinder 7 to ture 6 which carries the cylinder, thus leaving the end portions of the cylinder free to contract and expand longitudinally. In the form of my invention illustrated in Figures 1 and 3 the belt portion 8 contains. ports 9 for the admission of scavenging air and exhaust ports 10 for the escape of the burnt gases, said ports 9 and 10 leading into the interior of the cylinder 7. In the engine show in Figure 1 the scavenging-ports 9 are height or length is that the double acting piston will always first uncover the scavenging ports before opening the exhaust. The cylinder 7 is secured rigidly to the frame member 6 by bolts or other suitable fastening devices 11 which pass vertically through the belt portion of the cylinder. Consequently, the belt 8, in addition to serving as a suitable means for the location of the scavenging and exhaust ports, also serves as a medium by which the. cylinder is secured in a plane normal to the axis of the cylinder to the top face of the frame member 6.

The cylinder 7 is preferably mounted on the frame member 6 in such a manner. that it can be adjusted laterally slightly with relation to the supporting member 6 during the operation of lining up the cylinder with its co-operating crank, this being accomplished by providing the frame member 6 with an opening of such diameter that a clearance 12 will be provided between the frame member 6 and the lower portion of the cylinder which projects downwardly into the opening in said frame member. The lower end portion of the cylinder 7 is centered or held in spaced relation with the side walls of the opening 12 in the frame member 6 by a centering device which preferably consists of a flanged ring 13 that has a sliding fit with the lower end portion .of the cylinder 7 and which is secured by means of bolts or other suitable fastening devices 14 against a machined surface on the underside of the frame member 6 which is parallel to a machined surface on the top side of said frame member on which the belt portion 8 of the cylinder rests. Accordingly, the lower end of the cylinder 7 is free to expand and contract longitudinally in accordance to the temperature influences manifesting themselves during the opera ion of the engine, Instead Of using a cens the supporting struccylinder 7 tering device for the lower end of the cylinder consisting of a ring or other suitable element -13tha't is the frame member 6, the lower end portion of the opening in the frame member 6 which receives the cylinder 7 may be bored out so as to form an integral portion '15 on the frame member 6, as shown. in Figure 2 that centers the lower end portion of the cylinder, but permits it to expand and contract longitudinally. While in this case the freedom for lateral adjustment in the position of the cylinder 7 relative to the frame member 6 is sacrificed, the feature of fredom of longitudinal expansion and contraction of the lower end portion of the cylinder is still retained. A

The upper end portion of the cylinder 7. is surrounded by a separate jacket wall l6 rigidly secured to the top face of the belt portion 8 on the cylinder by the bolts 11 which secure said member 6, and provided at its upper end with a ring-shaped portion 17 that surrounds the extreme upper end of the cylinder. Accordingly, the upper half of the cylinder 7 is free to contract and expand longitudinally in accordance to the temperatures occurring incidentally to the operation of the engine. The opposite ends of the are 'closed by heads '18 and 19 which are preferably secured to the cylinder by means of bolts 20 screwed into the ends of the cylinder.

The belt portion 8 of. the cylinder is surrounded bya scavenging air receiver which may be built up of plates 21, as shown in Figures 1 and 3. This air receiver may either completely surround the belt portion of the cylinder, or it may go partially around this section of the cylinder far enough so as to include all of the circumferentially-disposed scavenging ports '9 through which air is admitted to the cylinder from the air receiver.

It is immaterial, so far as my broad idea is concerned, whether the cylinder is mounted upon or within the supporting member that carries the cylinder, and it is also immaterial whether the inner wall of the cylinder is formed by a single member the. full height of the cylinder or by a plurality of members connected together, .so long as the joint between said members will not impair the free contraction and expansion of the inner cylinder wall. Therefore, in Figure 4 of the drawings I have illustrated an engine constructed in accordancewith my present invention which differs from the engine shown in Figure 1 in that the belt portion 8 of the cylinder a is arranged within instead of on top of the frame member 6 and is rigidly connected by bolts or other suitable fastening devices 11 to a horizontallydisposed, machined surface on the in erior detachably connected to belt portion to the frame upper face of said frame member.

of said frame member 6 which extends parallel to a machined surface on the top or The practically completely surand the opening in said frame member which receives the cylinder is of such diameter that a clearance space 12 is provided between the cylinder and the side wall of said opening so as to permit of lateral adjustment of the cylinder relative to the frame member 6*. The extreme upper end portion of the cylinder is centered or held in spaced relation with the frame member 6 by a centering device 16*, preferably a flangedwring, rigidly connected 'to the frame member 6 and having a sliding fit with the upper end portion of the cylinder which it embraces, so as to permit the cylinder to expand and contract longitudinally, said ring 16 also forming part of the outer wall or water jacket of the cylinder. If desired, the centering device that surrounds frame member 6 rounds the cylinder,

' the upper portion of the cylinder may consist of an integral. portion 16 on the frame member 6*, as shown in Figure 5, that is bored out so as to snugly embrace the extreme upper end portion of the cylinder 7*. In this case the feature of lateral adjustment is again sacrificed, without, however, impairing the provision for freedom for longitudinal expansion and contraction of the cylinder.

The portion of the cylinder extending below the belt portion S is surrounded by a separate water jacket member 22 whose upper end is rigidly connected to the belt portion 8 by the bolts 11 which secure said belt portion to the frame member 6 and whose lower endhas a -sliding fit with the lower end portion 'of the cylinder, thus permitting the cylinder to expand and contract longitudinally. If desired,- the 'lower end portion of the cylinder that is embraced by the water jacket member 22 may consist of an integral water jacket portion 22 on the cylinder. Instead of making the inner wall of the cylinder in one piece, as in the form of my invention illustrated in Figure 1, the cylinder may be formed in two sections, as shown in Figure 4, the lower section consisting of a separate casting that is secured to the upper section 7 of the cylinder by shrink links 23 or other suitable devices before machining, a method extensively applied on large gas engine cylinders. To all intents and purposes a one-piece cylinder is thus obtained with this characteristic feature,-that the cylinder is rigidly held to the frame structure by means of a centrally located belt portion and is permitted to expand and contract freely towards either end from the centrally located fastening means of the cylinder. In the engine shown in Figure 4 the interior of the frame-member 6 also forms a scavenging air receiver that completely surrounds invention, various modifications are possible which are not herein illustrated. For instance, instead of providing sliding joints for the ends of the cylinder through bored holes, annular flexible diaphragms may be used to close the end or ends of a water jacket space between the cylinder and a surrounding water jacket wall. Also the cylinder mounting may be modified by interposing between the belt portion of each cylinder and the supporting frame anextra section which may be of circular or any other form in horizontal cross section. Any such section, whether forming merely an integral section of the outer wall or water jacket of the belt portion, or whether inserted as an individual piece, will always virtually amount to a rigid connection between the engine frame and the cylinder about the cylinders centrally located beltand in a plane normal to the axis of the cylinder, without, of course, impairing the freedom for longitudinal contraction and expansion of the cylinder.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1'. A doubleacting internal combustion engine provided with a acketed cylinder having an inner wall whose central portion is rigidly connected to a supporting structure and whose end portions are free to expand and contract longitudinally with relation to the jacket.

2. A double-acting internal combustion engine'provided with a cylinder having an inner wall whose end portions are free to expand and contract longitudinally and whose central portion is rigidly connected to a supporting structure in such a manner that the cylinder can be adjusted :laterally slightly with relation to said supporting structure during the operation of lining up the cylinder with its co-operating crank.

3. A double-acting internal combustion engine, comprising a cylinder having an inner wall, a supporting-structure that carries said cylinder, means for rigidly. connecting the central or intermediate portion of the inner wall of the cylinder to the supportin structure, and means for centering or hol ing the end portions of the cylinder without interferi-ng wlth the longitudinal expansion and contraction of the cylinder.

and outer walls and 4. A double-acting internal combustion engine, comprising a cylinder, a supporting structure carrying said cylinder and so arranged that the cylinder can be adjusted laterally slightly with relation to same during the operation of lining upthe cylinder with its cooperating crank, means located at approximately the center of the cylinder for rigidly connecting the same to said supporting structure, andstationary centering devices that have a sliding fit with the end portions of the cylinder.

5. A double-acting internal combustion engine having a cylinder equipped with an inner Wall that is provided intermediate its ends with an integral portion that is used for rigidly connecting the cylinder to a supporting structure, the end portions of the cylinder being free to expand and contract longitudinally.

6. A double-acting internal combustion engine, comprising a supporting structure, a cylinder whose inner wall is provided'intel mediate its ends with an integral portion that is rigidly connected to said supporting structure, and centering devices thatembracethe end portions of the cylinder but which do not interfere with the longitudinal expansion and contraction of the cyliner. 7. A double-acting internal combustion engine, comprising a frame member having a horizontally-disposed, machined surface, a cylinder whose inner wall is provided intermediate its ends with an integral portion that bears against said machined surface and which is rigidly connected to same, and holding devices at the ends of said cylinder arranged in telescopic relation with the cyliner. 8. A double-acting internal combustion engine having a cylinder provided with inner with -a centrally arranged belt portion connected to the inner wall and equipped with scavenging and exhaust-ports, and means combined with said belt portion for connecting the cylinder to the supporting structure that carries same.

9. A double-acting internal combustion engine, comprising a cylinder whose inner wall is provided with a centrally arranged belt portion that contains scavenging and exhaust ports, a supporting structure to which said belt portion is rigidly connected, and centering devices for the end portions of the cylinder which permit the cylinder to expand and contract longitudinally.

10. A double-acting internal combustion engine, comprising a frame member, a cylinder carried by said frame member and constructed in such a manner that it can be adjusted laterally slightly with relation to said frame member during the operation of mounting the cylinder, said cylinder having a belt portion that contains scavenging and exhaust ports, and stationary centering devices that surround the end portion of the cylinder and which permit the cylinder to expand and contract longitudinally. I

11. A double-acting internal combustion engine, comprisinga frame member, a cylinder provided with an inner wall and a centrally arranged belt portion integrally coninected to the inner wall of the cylinder an ports, means for rigidly connecting the belt portion of the cylinder to said frame member, and a scavenging air receiver arranged in proximity to said belt portion and communicating with the scavenging ports therein.

12. A double-acting internal combustion engine, comprising a frame member, inder whose inner wall is formed by a provided at the center of the cylinder with an integral belt portion that contains scavenging and exhaust ports, fastening devices passing through said belt portion which secure the cylinder to the frame member,

containing scavenging and exhaust a cylmember the full height ofthe cylinder which is means for holding the end portions of the cylinder in spaced relation to said frame member without interfering with the longitudinal expansion and contraction of the cylinder, and a scavenging air receiver that surrounds the part of said belt portion in which the scavenging ports are formed.

HANS R. SETZ. 

